NC State Extension

Keys to Successful Corn Production

According to data presented by Dr. Ron Heiniger, NCSU Professor of Crop Science and Cropping Systems Specialist, the key elements of management for high corn yields within Eastern NC are: 1) proper planting dates; 2) hybrid selection; 3) plant population; 4) application of a starter fertilizer in a 2 X 2 or 2 X 3 placement to the seed; and, 5) proper nitrogen (N) rates applied according to soil type, hybrid potential and existing plant growth.

1)   Selection of planting dates should provide the highest probability of adequate soil moisture during early season growth and during critical reproduction stages. Avoidance of water stress during these critical stages is critical to high corn yield. Appropriate planting dates can be projected using a hybrid’s maturity group and projected climatic factors. Data providing climatic data can be found at http://agroclimate.org/. Historically, highest corn yield is achieved within Craven County when planted within the first two weeks of April or between May 10-20th.

2)   Hybrid selection is another critical component of high corn yields. Varieties must match realistic yield expectations (RYE) for the specific soil, anticipated planting dates, known pest problems, targeted plant population and appropriate level of management. Failure to consider all of these factors when selecting varieties can result in poor yield. North Carolina State University provides growers with historic varietal performance data through NCSU Official Variety Trials. This data is available through local Extension offices as well as at the web page, http://www.ncovt.com/. In addition to this data, many N.C. Cooperative Extension Agents have begun coordinating varietal trials. These trials provide data for the same varieties planted in multiple counties, planted to different soil types, planted with differing planting dates and using different management styles. This data is available for download HERE.

3)   Final plant population is critical. The population should be based upon the varieties historic yield potential, the soil type RYE, fertilization practices, probability of adequate water availability at reproduction stages and individual risk. Generally for this area, final plant population should range from 24,000 to 33,000 plants per acres. For soils with higher water holding capacity or irrigation capacity, a population as high as 43,000 plants per acres is acceptable.

Table 1, Planting population guidelines for different soil types with dryland and irrigated corn, shows seeding rate adjustments based upon soil type and soil water holding capacity as a guide. A handy chart estimating final corn populations based upon row width and plant spacing is available from the Clemson University website, http://www.clemson.edu/extension/rowcrops/corn/guide/plant_population.html

Table 1. Planting population guidelines for different soil types with dryland and irrigated corn.

SOIL TYPE

TEXTURE

WATER-HOLDING CAPACITY
(INCHES/INCH)

KERNEL DROP*
(X 1000)

FINAL STAND
(X 1000)

Dryland Corn

Wagram

loamy sand

0.09

19,800 (10.6)

18,000

Norfolk

sandy loam

0.11

22,000 (9.5)

20,000

Goldsboro

sandy clay loam

0.13

24,200 (8.6)

22,000

Hyde

shallow muck

0.20

30,000 (7.0)

27,000

Ponzer

muck

0.22

30,000 (7.0)

27,000

Irrigated Corn (with hose-reel or cable-tow machines)

Wagram

loamy sand

0.09

22,000 (9.5)

20,000

Norfolk

sandy loam

0.11

24,200 (8.6)

22,000

Goldsboro

sandy clay loam

0.13

26,400 (7.8)

24,000

Irrigated Corn (center pivot or linear move machines)

Wagram

loamy sand

0.09

31,900 (6.5)

29,000

Norfolk

sandy loam

0.11

31,900 (6.5)

29,000

Goldsboro

sandy clay loam

0.13

31,900 (6.5)

29,000

* 1) Based on 30-inch row spacing and 90% germination; 2) Numbers in parenthesis indicate number of inches between seeds

Source:  North Carolina Corn Production Guide, https://www.ces.ncsu.edu/plymouth/cropsci/cornguide/

 4) Utilization of a starter fertilizer has shown to increase yields. This fertilizer should be placed 2 -3 inches away from the seed and 2-3 inches deep. The blend should supply 20-30 lbs./ac of actual N and phosphorous (P). Higher rates of P do not increase yield and should be avoided, especially on soils with a NCDA & CS soil P-index above 100.

In addition to starter fertilization, some evidence supports the addition of in-furrow fertilization. These in-furrow fertilizers do not take the place of starter fertilizers. Rather they supply a very small amount of nutrients very near the germinating plant to promote rapid emergence and growth. Numerous blends are available with no strong support promoting one blend over another. It should be noted that additions to these in-furrow fertilization treatments might be detrimental. Additional products, especially those with ammonium-N sources, increase salt injury to seeds or alter soil pH within the microenvironment around the seed. Thus, additions are not recommended.

5. Proper N rates should reflect actual production history. Corn utilizes 1.0-1.25 lbs. of N for each bushel of grain produced. The actual value varies according to environmental circumstances, timing of application, placement of N and hybrid response. Generally, 30-40 lbs./ac of N at or near planting followed by the remaining N when corn is between the V6-V12 stages has produced highest yields. Split applications of N enhance corn yield as well as protect the environment since up to 35 percent of the total N used by the corn crop is utilized by the plant after pollination. Excess N applied early can be lost on sandy soils or with irrigated corn due to leaching, and on finer textured soils due to runoff.

If actual corn yield data is not available, RYE data for each soil type for county within NC is available at http://nutrients.soil.ncsu.edu/. Simply select the county, soil type and slope to determine RYE and N rates.

Additional corn production information is available at local Extension office, publications and the NCSU website, https://www.ces.ncsu.edu/plymouth/cropsci/cornguide/

Written By

Photo of Mike CarrollMike CarrollArea Agent, Agriculture (252) 633-1477 (Office) mike_carroll@ncsu.eduCraven County, North Carolina
Page Last Updated: 4 years ago
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